Current collector



June 4, 1929. sso

CURRENT COLLECTOR zFiled June 4, 1927 v 1 mm M EJEJVST A. LARssaN Gunmen Ennsr a. LAns'soN, or'mi ivsrrnim, onro, Asst error. TO TH oHIo'BRAss-oo or ansrrnnn, 01110, A oonronnrronornnw Jn'nsEY. i

MBANY,

' CURRENT oomtnctron.

Application filed June 4,

My invention relates to current collectors and to-th'attype of collector in which the con- Theobjectof my invention is, to provide a device of the character described, which will have an extended contact with the trolley wire and a large carrying capacity for current between the contacting element and. .the 7 support or harp therefor, *andone in which the tendency for the contacting element or shoe to rotate, 'when the shoe strikes an ob Stl'LlCtlOIl, is resisted. 1 l. Another object of my invention is to so arrange the shoe with respect to its support that the tendency to rotate fron friction of the shoe with the trolley wire is as small as possible Other objects will appear as the invention "is further described hereinafter.

My invention residesin the new anclnovel construction, combination and relation of the various. parts hereinafter described and shown in the accompanying drawing. 1 In the drawing: p 7

Fig. l is a top view of my invention. Fig. 2 is a side view of my invention. a

Fig. 3 is an end view. Fig. 4 is a longitudinal sect the line Hof Fig. 1.

ion taken on Fig. 5 is a transverse se'ction taken on the I line 5-5 of Fig. 2.

- coefficient of friction between the she It is well knownto thosejslrilled in the art that prior devices ofthis charactcr,inwhich a sliding contact or shoe is employed, are usuof which is removed quite a distance from the contact surface of the shoe with the; trolley wire. As later explained, this produces a strong tendency for the shoe to rotate if t-he coefiicient of friction oftlie shoe with respect to the trolleywireis equal or greater than the e and the 'axle or support. l i 3 V Some devices of this character eniploya flexible connection or cable between lth'e'shoe vand the supporting harp in order to conduct the current from the shoe tothe harp, as the axle, as a rule, gives very small carrying ca pacity and the contact is very poor. In order to avoid thejuse of a flexible cable. or $16.6

springs, I employ a relatively large axle,

, which gives a large area of, contact with the 7 shoe, and also the endsof the axle are quite the trolleywire as possible, taking intofaccount probable wear in the surface of the v ally mounted upon asmall axle,;the center- 1927." ScriaI- no. waste; 1'.

therefore,

trolley wire to the'harp without the use ofa flexible'cable or shuntaroundthe axle. At the same time, by" properly placing. the axis of the axle so that theiupperp'ointof contact of the axle withfthe-shoe-isfas close to the contact surfaceiof the shoe with shoe, I am ableto reduce very materiallythe tendency for the shoeto rotate'when moving along a" conductor. J

r In the preferred embodiment of myfinvenextensive in area and are secured in clos'eand [intimate- Contact with t-he supporting harp,

I am able with my device to safely v and eificientlycarry large currents from the tion I employ'a supporting harp "1', similar to] I those in use in'prior art, and'mounted be.- I

tween the inner faces of the arms'2 of the'harp,

I position an axle 3. In orderto hold the I. axle in, position, I employ two transversely disposed bolts 4; The end faces of the axle Y 3 and the inner faces of the arms 2; coacting therewith, I preferto machine so that I; will get the benefit of the full contactiarea of the ends of the axle and by means of'the bolts 4 I am able to draw the contacting surfaces into close and intimate relationwith ,each other; Transverselydisposed in the axle is a passage 5 which has. communicating therewith the smaller passages 6 which'openupon the surface of the axle, and before mounting the axle in' thefharp'Ifill the passage 5: with i p a. lubricating I grease whichhas a. tendency, p

.to work its-way through the small or passages 6to the surface of thegaxle. '2 1 tweenthe flanges-9 and having theelongated surface 10 which contacts with the; trolley Mounted. upon the axle3" is a shoe. 7 pro-j vided with an extended groove 8 formed ,be-

wire; The shoe is provided with atransverse opening of sufficient size to snugly, fit the axle a i 3, but permitting relativerotation of the shoe with. respect to the axle when the shoe isin operation'and. any difliculties in the wire or varying height of the trolley wire requirea rotation of the shoe relative, tothe axle;

ice

I I construct my shoe with a certain, amount of metal below. the groove-8 'to'all ow for wear, and this. metal may amount to possibly 1/4 -l/Vith this in mind, if thelinellrepresents the maximum limitof wear of the shoe, I drill thetransverse hole through-the shoe with its upper surface very close tothe line 11, which tact surface 10 when the shoe is new, thereby bringing the upper surface of the axleas close to the line of contact with the wireaspracticable, and wnere the shoe is made ofihardene d steel, it is practicable tobringthe axle surface much closerto' the surface than where the shoe is of copper orbronze. The ob ect of bringing the surface of the axle as close to the wearing surface ofthe shoe as possible is to reduce the moment tend- ,mg to rotate thezshoe when the shoe is inn-1og-tion sliding along the trolley wire, and the results of so positioning the axle with re- ,spect tothe contact surface of the sh'oecan be shoe.

shoe;

shown by the following simple mathematics.

D=distance from center of axle to contact surface.

R =radius'of axle. a=coefficlent of friction between wireand b =coetficient of friction between axleland P=pressureof shoe against wire.

3 P X a X11) :moment tending to :rotate shoe.

P X Z) X R equal moment :tending'ito resist rotation of shoe.

P X a X D- P X 2) X R actual inomentltending to rotate; shoe.

If,a..=b :then

' P a R) actualnioment tendingto ro- "tate shoe.

v Pa (1 P a actual momentiten'd-e ing'torotate shoe when a=' Z). i i

If there is.a difference .1

frictionthen V n the coefficient of l =P (a- 1)) represents the moment tending :to rot-atethe shoe.

"If thezaxle were made of small diameter with its axis as shown inrFig. 4, then the tendency; torotate-would bevery -much greater than shown above,:as:for instan'ce,

If D 1 landpli l andab then P 1+V 1a, and it will'benoted "thatthis moment' is, three times; that f; given above where. the surface of the axle ap';

,approaches closely to the contact surface of the shoe. J

. If,' of course, there is a difference in the coetlicient of friction, then'th'e momenttending to rotate-theshoewould beP (e /4 Ifit were possible to havethe-surface of the axle and the contactsurface coincide, in

- which case R and "D wouldboth 1, then 2 Pa (11) would=zero, or'in other words, there would be no-moment tending .to rotate the shoe unless 5 there was a difference in} the coefficient of friction.

It isbelieved fromjtheabove it-willbe seen thatby 'properly'locating the axis of the axle '5 and the diameter of: the axle with respect to.

" the surface of theshoe,-that'the tendency to rotate the-shoe can bebrought down to-am'inimum and governedlargely' by the; coeliicient of frictionjinthe moving parts- -and the shoe.

amount of wearnecessary to'allow for in the V In orderto make the shoe operative in bothdirections, as when applied to a moving vehicle, I place the .axis of the axle such that under normal operation it will rest in a transverse vertical plane coinciding Wlt-ll' a verti cal centerline 00 pass1ng through the axis and will cutthe contact surface midway of its length, as shown in Fig. i; c This makes the forwardand backward operation'of the shoe uniform, as the parts are then symmetrical with respect to'the transverse vertical plane and vertical center line 00 as will be noted 1n the drawing. In order to reslst-tendency for'the shoe to rotate when it strikes obstructions, such as the: end of a trolley ear and V tend to eliminate such rotation, in the majorityof cases I employ what 1 term a stabi- 'lizer 12,.Which is shown in Fig. 4 as a ,sepa-- rate element secured to the shoe means of bolts 13. Thisstabilizer alsoi acts as a guard; to prevent the shoe catching on the'trolley.

wire should the shoe leave the trolley wire. The bolts 13, if desired,may havetheirheads counter-sunk below the surfaceof thestabi-j lizer, which will then give a perfectly smooth surface, also, if desired, thestabiIiZermaybe formed as an integral unit with the shoe.

When in normal operation, thecontact between the shoe andthe trolley wire will cause the stabilizer to assume'its lowest position,

and it willbe noted that the mass of the stabiliz er is greatest at its lowest point, therefore, should the forward end of the shoesuddenly strike an inequality in thetrolley wire, then there would be a sudden tendency for the shoe to rotate, butsimultaneously there-would be a tendency for the stabilizer with its mass located'at its lowest point to rotate, and it would require a forceito start moving the mass ofthe stabilizer, which would tend to counteract the tendency for the shoe to -ro T tatedue to its 'havingsuddenly met with an inequality along-the wire. 7

I have so formed-the stabilizer j that the upper portion orarms 1-4 form with the rim f the shoe'arcuatespaces '16, and passing through the armsof the .harpand one of the arcuate spaces 16 is a pin'17 which engages 4 the shoulders '18- and 19' on-fthe shoe and stabilizer respectively to limit the amount of rotati'onof theshoe under abnormal conthe stabilizer would maintain the contact-surface of the shoe in a horizontal position when the shoewas not engaging the trolley wire,

but I make no attempt to -adjust the weight of the shoe to bring about this condition, as it is not necessary 1n the successful operation of my device,-but the mass of the shoe a is adjusted so as to overcome the tendency of ing to receive an axle therein, the horizontal amount of oscillation of the shoe on its axle, means in the axle to retain a lubricant and [means communicating with the said means 7 and the bearing surface of the axle;

, havingjits mass substantially equally dis the shoe to rotate when suddenly meeting with obstructions in its path of movement.

' I find that the diameter of the axle should;

comprising a shoe having a groove with an elongated contact-surface, a transverse openaxis of the axle being located in a vertical transverse plane at right angles to the contact surface and midway ofthe length of the con- -tact surface, shoe being'symmetrical withrespect tothe transverse plane and the said axis being below the contact surface a distance not to exceed the radius of the; axle plus an amount equal to the predetermined allowable wear of the shoe, a support, .an

axle mounted inrthetransverse opening and secured to the support in fixed relation,- a separably formed U-shaped stabilizer secured to the shoe with its center of gravity positioned in said vertical plane but below the axis of the axle and its legs. projecting upwardly and forming guards, a transversely disposed member 's'ecuredto the support and arranged to engage a shoulder on the shoe and a shoulder on the stabilizer to limit the 2. A current collector comprising a shoe posed on both sides of a vertical central axis,

. a groove having anelongated contact surface extending equal distance to each side of the said vertical axis, a transversely disposed passage through the shoe, an axle mounted in the passage with its axis 111 the plane of said vertical axis and the upper-line of contact between the axle and the shoe being on the said vertical axis and adjacent the contact surfaceon the shoe, a support, means securing the axle to the support in pivotal relation to the shoe, means to limit the amount of pivotal motion and an inverted U-shaped stabilizer secured to the shoe and having the bulk of its mass positioned below the lower line of contact between the'axle and the shoe and on the vertical axis to resist a sudden tendency of the shoe to rotate and the distribution of the Weight of the said parts being substantially equal both forwardly and rearwardly of the vertical'axis.

. 3. A current collector comprising a sliding shoe having a flanged groove with an elon;

is parallel.

.7. A metallic'current collecting shoe provided with a grooved portion having an elon re n gatedcontact surface' substantiallyequally' spaced on each side of a vertical-central axis, v a transverse passage through the; shoe, an

axle mounted in the passage and'secured to a support, the upper line of contact between the i axle and the shoe' cut by thesaid'vertical axis being positioned adjacent the surfaceof contact of the groove, the axis of the axle being I cut by the said vertical axis and a U-shaped stabilizer with its mass suspended 'bel'ow'the I 1 axis of the axle and equally spaced withreaspect to the'vertical axis and longitudinally shoe to rotate; ,1 a q 4. A current collector comprising 'aYha'rp of the shoe to resist sudden tendencies ofthe with means to secure it to a support and other spaced projecting arms having inner parallel faces, an'axle mountedbetween said faces and- Y secured to the armsYwith the end faces of the I axle engaging the faces of the arms, a plura'l ity of spaced and transversely disposed means to hold'thefaxle in place between the arms and prevent it's-rotationand a sliding shoe with a contact face pivotally mounted upon the axle, the diameter'of'the. axle being? more than twice the thickness'of metal between the contact face and the nearest adjacent edge of the axle. I j 5. A current collector comprisingja harp with means to secure it to a support, spaced arms projecting from the said means and having inner parallel faces, an axle mounted between the arms and having parallel faces engaging the faces of the arms, avpair of transversely disposed means to draw the arms toward the axle to'bring adjacent faces into firm and secure engagement and prevent rotation of the; axle, a shoe pivotally mounted upon the axle and means to limit the pivotal action of the shoe. a

6. A metalliccurrent collecting shoe provided with a grooved portion having an elongated surface to engage a conductor in sliding'relation thereto'and subject to wear, a. i i

transverse passage therethrough to receive an axle upon wh ch the shoels mounted and pivots, the diameter of the passage to be substantially not less than the length of the original contact surface engaging the conductor and a removable membersecured to the shoe tending to hold the contact surface parallel to the conductor when the conductor gated/contact surface to engage acond'utcor and extending an equal distance to both sides i of a vertical centeraxis and sub ect to wear,

a transverse passage therethrough to receive an axle upon which the shoepivots, theaxis of the-passage being located on the vertical center axis and the diameter of the passage to be substantially not less than the length of the original contact surface engaging the.

conductor and means to maintain the con.-.

tact surface in a horizontal position when oh" the hcondnctor.

8. A metallic current collecting shoe pro Yidedsiiith a grooved portion having an eloni which the Shoe vpivots vhaving its center liponsaid line, the ainoiint of metal in the shoe between the contact surface-when new .and theadJaCent edge of the passage cut by said ertical axis to he not inoife than inch and the diameter of theaxle to he, stibs tantiallynot'less than the length otthe original Contact surface engaging the conductor.

51-9. A metallic ciirrent collecting shoe pro' vided with agroovedportion having an elongated contact suriac'e-to engage a conductor and subject towear and extending an equal d stance to both sldes ot a vert caleenter axis,

a transverse passage to receivean axle upon which the shoe pivots and having its center npon said-line, the amount of metal iii the 'shoebetween the contact surface when new an dzthe adjacent edge of the passage cut by said Vertical axis tobenot more'than inch and the diameter of the axle to he substantially not less than the length of the original contact surface engaging the Conductor and a stabilizer to reslst sudden tendencies V of the shoe to rotate. a

10. A current collector comprising a shoe having a fian ged groove with an eloi gated contactsuriace to engage a conductor in tric- 'tional sliding relation thereto and subject to Wear, an axle uponwhich the shoe is pivotally mounted, the axis or theaxle being midway. the length of the contactsurtaca the distanceof the axis "from th'e'contact stir-- vface and the radius of the axle being inthe ratio of 1 to A.

v 11. A current collecting shoe providedwith a groove having an elongated contact surface,van;axle upon which the shoe pivot-s and a stabilizer, the eflective inassfof the stabilizer being positioned below the axis of axle and the stabilizer being equallydi'sposed on both sides of a vertical central axis which isfcentral ofthe length ofthe contact suri'ac'e.

Intestimony whereot'l my signature ERNST ALABSSON; j

theaxle and the mass of each the shoe, the i 

